Boiler installation



2 Sheets-Sheet 1 W. L. DE BAUFRE BOILER INSTALLATION Filed June 29, 1929 Sept. 24, 1935.

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Sept- 24 1935 w. L. DE BAUFRE BOILER INSTALLATION Filed June 29, 1929 2 Sheets-Sheet 2 INVENTOR M .K AZ

BY 'n/Ml ATToRNEYs' Patented Sept. 24, 1935 2,015,338 BoILER INSTALLATION William L. De Baufre, Orange, N. J., assignor to International Combustion Engineering Corporation, New York, N. Y., a corporation of Delaware Application June 29, 1929, Serial No. 374,716 10 Claims. (Cl. 122-235) This invention relates Ato improvements in boiler installations having steam evaporating elements in their combustion chambers and employing boilers of the bent tube type having upper steam and water drums, lower mud drums and banks of tubes connecting the drums.

One of the primary objects of the invention is the provision of a boiler installation of the above character having improved natural circulation.

Another object resides in, improvements in the arrangement of the connecting tubes of the boiler. l,

A further object resides in improvements in the manner of connecting the combustion chamber steam evaporating elements to the boiler of the installation.

How the foregoing, together with such other objects and advantages as may hereinafter appear, or are incident to my invention, are realized is illustrated in preferred form in the accompanying drawings, wherein- Fig. 1 is a vertical section through a boiler installation .embodying my improvements. n

Fig. 2 is a fragmentary view of a modication of the invention, and

Fig. 3 is a fragmentary view of still another modification.

The installation comprises in general a boiler A of the bent tube type, a combustion chamber B located in front of and beneath the boiler A, burner means C, in this instance located in the front wall of the installation for introducing fuel, preferably pulverized coal, into the combustion chamber to be burned in spacev therein, .and an oitake D for exit of the burntl products of combustion and a lower ash pit E.

The boiler A comprises a lower mud drum 4 and a plurality of upper steam and water drums, i. e., a front upper drum 5, a middle upper'drum 6, and a rear upper drum 1, and front, middle and rear banks of tubes 8, 9 and Ill for connecting the lower drum to the upper drums. The

front bank of boiler tubes 8 is divided into two groups, the front group II comprising a plurality of rows of `tubes connected at their lower ends into the lower drum 4 and at their upper ends into th upper drum 5, and a rear group I2 comprising-la'plurality of rows of tubes connected at their lower ends into the drum 4 and at their group of tubes I4 comprising a plurality of rows of tubes connected at their lower ends into the lower drum 4 and at their upper ends into the upper drum 6. The rear bank of tubes I0 comprises a plurality of rows of tubes connected at 5.

they are aligned in rows crosswise of the boiler 10* and also in planes perpendicular to the axes of the drums. The tubes of the rear group I2 of the front bank 8 and the tubes of the front group I3 of the middle bank 9 are bent at their upper portions so that they cross each other in-15 the upper portion of the boiler as indicated at I 5.

The upper drums 5 `and 6, and 6 and l, are connected together by means of a plurality of water circulators I6 and by a plurality of steam circulators I'I, and a steam outlet I 8 is provided 20 for the rear upper drum l.

The boiler A is provided with suitable bafliing indicated at a, b, which is arranged to cause the gases of combustion to pass upwardly of the front bank 8, then downwardly of the middle 25 bank 9, then upwardly of the rear bank Ill, and finally discharge through the oitake D.

The combustion space of the combustion chamber B is largely defined by steam evaporating surfaces, and, in this instance, I have shown the side 30 walls, only one of which appears in the drawings, lined by tw'o sets of upright boiler tubes I9 and 20, the lower ends of th'e tubes of both sets being connected into a lower header 2| and the upper ends of the tubes of the set I 9 being connected into an 3.5 upper header 22, and the upper ends of thel tubes of the set 20 being connected into an upper header 23. The rear wall of the combustion chamber is largely defined by a row of upright tubes 24 which are bent at their upper portions so as to extend 40 in front of and in parallelism to the tubes of the front bank 8 as indicated at 25. These tubes are connected at their upper ends into the frontl upper drum 5. The bottom of the combustion space is defined by a row of tubes 26 extending 45 across the bottom of the combustion chamber and inclined somewhat from front to rear. The tubes 2li are spaced suiiiciently widely apart to-permit that the lower end portions of the tubes 24 are bent outwardly and downwardly for connection into the junction boxes 28.

Water is led to the side wall tubes of the sets I and 20 from the lower drum 4 of the boiler by; means of downcomers 29 leading from the drum' to the lower headers 2l and water is led to the bottom and rear screens. and 24 from the mud drum 4 by means of downcomers 30 leading from the mud drum to the outside header 21. The upper headers 22 of the sets of side wall tubes Il are connected to the upper front steam and waten drum by means of a plurality of upcomer tubes 3l and the upper headers 23 of the sets of side' wall tubes are connected to the upper middle steam and water drum 6 by means of a plurality of upcomers 32. From the foregoing it `will be seen that the circulation is from the mud drum 4 to the header 21, then upwardly through the tubes 26, then upwardly through the tubes 24 and the inclined portions thereof, and nally into the4 upper drum 5. The circulation in the side wall. screens is upward and the delivery thereof is divided between the front and middle drums 5 and C, the sets I9 delivering into the front upper drum l and the sets 20 delivering into the middle upperdrum 6.

The circulation of the boiler unit A is upward in the tubes of the front group Il of the front bank I from the drum 4 to the drum 5, upward in the tubes of the rear group I 2 of the front bank 8 from the drum 4 to the middle upper drum A6 downward in the front group'of the middle bank 9 from the upper drum 5 to the mud drum 4, downward in the rear group of the middle bank 9 from the middleI drum 8 to the mud drum 4, and downward in the tubes of the rear bank I0 from the rear upper drum 1 to the mud drum 4.

From the foregoing, it will be seen that tubes from the mud drum to the front steam drum form part of the middle tube bank, and that cross tubes from the mud drum 4 to the middle upper drum,

6 form part of the front tube bank, and that the water walls of the combustion chamber discharge steam into both the front and middle steam drumsI 5 and. 6 while circulating water for these walls is drawn from the mud drum 4. The arrangement is very advantageous in that better natural circulation is afforded by providing a direct connection from the front steam drum to the mud drum through tubes in the middle tube bank where generation of steam is not as active as in the front tube bank. Without these cross tubes the water separated from the steam liberated in the front steam drum must return, either through short curved tubes to the middle steam drum and thence through the middle tube bank back to the mud drum, or must pass directly down through the tubes in the front bank where steam generation is .very rapid. In either case the circulation is restricted, the water'level in the front drum being too high and the steam water ratio in the radiant heating surfaces reaching values which might be dangerous. The cross-over tubes provide useful heating surface for the return circuit tothe water walls and front tube bank which are connected to the mud drum.

The distribution of the delivery from the radiant heat tubes between the two front drums is also advantageous in securing proper water levels in both drums and preventing the overloading of the front drum. In this connection, by virtueof the provision of the tubes I3 connecting the front steam and water drum to the mud drum, it is possible te have more of the radiant heat tubes deliver to the front steam and water drum, than to the middle steam and water drum, without danger of overloading.

Referring to the modification illustrated in Fig. 2, it will be noted that the tube intersections of 5 the crossing tubes of the front and middle banks 8 and 9 are arranged well up in the boiler so that the products of combustion may pass mainly below the tube intersections in passing from the front bank over the baille a to the second bank. 10

In the modification illustrated in Fig. 3, all of i the tubes of the front bank 8a connect intq the upper front drum 5a, while the middle bank 9a is divided into two groups as before, the front group of tubes connecting at their upper ends into the l5 drum 5a and the rear'group of tubes connecting at their upper ends into the middle drum la. Water circulators Ita are connected between the upper drums 5a and 6a and between the upper drums 6a. and la. The steam space of the upper 20 front drum 5a is connected to the steam space of the upper rear drum 1a by means of a plurality of steam circulators Ha, and the steam space of the middle upper drum 6a is connected to the steam-space of the rear upper drum 1a by 25 means of a plurality of steam circulators llb. In this modification I have shown all of the side wall tubes of the combustion chamber connected for delivery into the middle upper drum 6a by means of a plurality of upcomers lla and 32a. 30 Otherwise the arrangement is the same as that shown in Fig. 1.

I claim:-

1. In combination, a bent tube boiler including a lower mud drum, front, middle, and rear upper 35 steam and water drums, front, middle, and rear banks of connecting tubes, the tubes of the front and middle bank being arranged so that both the front and middle upper drums are connected to the mud drum by tubes in both the front and middle banks; a. combustion chamber located in front of and beneath said boiler; boiler tubes defining combustion space ofl said combustion chamber; upcomer means from said boiler tubes to both the front and middle upper drums; and downcomer means from the mud drum to said boiler tubes.

2. In combination, a bent tube boiler including a lower 4mud drum, a first and second upperv steam and water drum, and. boiler tubes connecting the mud drum to the upper steam and water drums, certain tubes connecting the mud' drum to the second upper drum being grouped with tubes connecting the mud drum te the first upper drum and constituting therewith a rst tube bank and certain tubes connecting the mud drum to the first upper drum being grouped with tubes connecting the mud drum to the second upper drum and constituting therewith a. second tube bank; a combustion chamber located in front of and beneath said boiler; boiler tubes marginal of combustion space of said combustion chamber and subject to high heat; downcomer means leading from the lower mud drum to said boiler tubes; upcomer means leading from said boiler 5 tubes to both the first and -second upper drums; and means for introducing fuel into the combustion chamber to be burned in space therein.

3. In combination, a water tube boiler including a pair of upper steam and water drums, a lower 7 mud drum, and banks of boiler tubes connecting the mud drum to said upper drums, each bank comprising a plurality of tubes connecting the mud drum to one of the upper drums and a plurality of tubes connecting the mud drum to 7| the other upper drum; a combustion chamber associated with said boiler;.radiant heat tubes in said combustion chamber marginal of com'- bustion space thereof; downcomer means leading from the lower mud drum to said radiant heat tubes; upcomer means leading from said radiant heat tubes to both of the upper steam and water drums; and means for introducing fuel into the combustion chamber to be burned in space therein.

4. In combination, a water tube boiler including a pair of upper steam and water drums, a lower mud drum, and banks of boiler tubes connecting the mud drlmi to said upper drums, each bank comprising a plurality of tubes connecting the mud drum to one of the upper drums and a plurality of tubes connecting the mud drum tothe other upper drum; a combustion chamber associated with said boiler; radiant heat tubes defining the side walls of said combustion chamber; radiant heat tubes extending across the bottom of said combustion chamber; radiant heat tubes dening the rear wall of the combustion chamber and connected to deliver in the iirst upper drum; means connecting the bottom radiant heat tubes to said rear wall tubes; downcomer means for supplying water to the bottom tubes from the mud drum; downcomer means for supplying water to the side wall tubes from the mud drum; upcomer means connecting certain side wall tubes for delivery into the iirst upper drum; upcomer means connecting the remaining side wall tubes for delivery into the second upper drum; and means for introducing fuel into the combustion chamber to be burned in space therein.

5. In combination, a bent tube boiler including a lower mud drum, front, middle, and rear upper steam and water drums, front, middle, and rear banks of connecting tubes, the tubes of. the front and middle bank being arranged so that both the front and middle upper 'drums are connected to the mud drum by tubes in both the front and middle banks, the tubes of the rear bank connecting the mud drum and rear upper drum,

, water circulators connecting the front and middle drums and the middle and rear drums, steam circulators connecting the front and rear upper drums, and steam circulators connecting the middle and rea'r upper drums; a combustion chamber associated with the boiler; boiler tubes dening combustion space of said combustion chamber; downcomer means from the mud drum to said boiler tubes; upcomer means from said boiler tubes to both the front and middle upper drums; and means for introducing fuel into the combustion chamber to be burned in space therein.

6. In combination, a bent -tube boiler including a lower mud drum', front, middle and rear upper steam and water drums, front, middle and rear banks of connecting tubes, .the tubes of the middle bank being arranged so that both the front and middle upper drums are connected to the mud drum by tubes in said bank, a combustion chamber associated with the boiler,'boi1er tubes defining combustion space of said combustonchamber, upcomer means from said boiler tubes to the second upper drum, downcomer means from the mud drum to said boiler tubes, and steam and water circulators connecting the upper steam and water drums.

7. In combination, a bent tube boiler includ. 5

ing a lower mud drum, a rst and second upper steam and water drum, and boiler tubes connecting the mud drum to the upper steam and water drums, certain tubes connecting the mud drum to the second upper drum being grouped with tubes 10 connecting the mud drum to the first upper drum and constituting therewith a rst tube bank and certain tubes connecting the mud drum to the first upper drum being grouped with tubes connecting the mud drum to the second upper drum l5 and constituting therewith a second tube bank;

a combustion chamber located in front of and beneath said boiler; boiler tubes marginal of combustion space of said combustion chamber and subject to high heat; downcomer means 20 leading from the lower mud drum to said boiler tubes; and upcomer means leading from said boiler tubes to both the first and second upper drums. e

8. In combination, a water tube boiler including a pair of upper steam and water drums, a lower mud drum, and banks of boiler tubes connecting the mud drum to said upper drums, each bank comprsing a plurality of tubes connecting the mud drum to one of the upper drums and a plurality of tubes connecting -the mud drum to the other upper drum; a combustion chamber associated with said boiler; radiant heat tubes in said combustion chamber marginal of combustion space thereof; downcomer means leading from the boiler to said radiant heat tubes; and upcomer Vmeans leading from said radiant heat tubes to the boiler.

9. In combination, a bent tube boiler including a lower mud drum, front, middle, and rear upper steam and water drums, front, middle, and rear banks of connecting tubes, the tubes of the front and middle bank being arranged so that both lthe front and middle upper drums are connected to the mud drum by tubes in both the front and middle'banks, the tubes of the rear bank connecting the mud drum and rear upper drum, steam circulators connecting the front and rear upper drums, and steam circulators connecting the middle and rear upper drums; a combustion chamber associated with the boiler; boil-v er tubes defining combustion space of said combustion chamber; downcomer means from said boiler to said last mentioned boiler tubes; and upcomer means from said last mentioned boiler tubes to said boiler.

10. A bent tube boiler having two main natural circulation systems, each of said circulation systems including a steam and water drum, a group of upcomer tubes, and a group of downcomer tubes, and means providing first and second gas passes in said boiler, said upcomer tubes of said two systems being located in the rst gas pass and said downcomer tubes of said two systems being located in the second gas pass.

WILLIAM L. DE BAUFRE. 

